Description of problem:
Upgrading Satellite 6.2 to 6.3.1 fails during pulp migration:
---
[DEBUG 2018-04-25 10:53:10 main] Found the following type definitions that were not present in the update collection [node, repository]
[DEBUG 2018-04-25 10:53:10 main] Content types loaded.
[DEBUG 2018-04-25 10:53:12 main] Applying pulp_rpm.plugins.migrations version 300

[DEBUG 2018-04-25 11:18:47 main] Applying migration pulp_rpm.plugins.migrations.0300_upstream_0033_checksums_and_templates failed.
[DEBUG 2018-04-25 11:18:47 main] Halting migrations due to a migration failure.
[DEBUG 2018-04-25 11:18:47 main] Cursor not found, cursor id: 164658109027
[DEBUG 2018-04-25 11:18:47 main] Traceback (most recent call last):
[DEBUG 2018-04-25 11:18:47 main]   File "/usr/lib/python2.7/site-packages/pulp/server/db/manage.py", line 235, in main
[DEBUG 2018-04-25 11:18:47 main]     return _auto_manage_db(options)
[DEBUG 2018-04-25 11:18:47 main]   File "/usr/lib/python2.7/site-packages/pulp/server/db/manage.py", line 302, in _auto_manage_db
[DEBUG 2018-04-25 11:18:47 main]     migrate_database(options)
[DEBUG 2018-04-25 11:18:47 main]   File "/usr/lib/python2.7/site-packages/pulp/server/db/manage.py", line 129, in migrate_database
[DEBUG 2018-04-25 11:18:47 main]     update_current_version=not options.test)
[DEBUG 2018-04-25 11:18:47 main]   File "/usr/lib/python2.7/site-packages/pulp/server/db/migrate/models.py", line 186, in apply_migration
[DEBUG 2018-04-25 11:18:47 main]     migration.migrate()
[DEBUG 2018-04-25 11:18:47 main]   File "/usr/lib/python2.7/site-packages/pulp_rpm/plugins/migrations/0300_upstream_0033_checksums_and_templates.py", line 47, in migrate
[DEBUG 2018-04-25 11:18:47 main]     for rpm in rpm_collection.find({}, ['checksum', 'checksumtype', 'repodata']):
[DEBUG 2018-04-25 11:18:47 main]   File "/usr/lib64/python2.7/site-packages/pymongo/cursor.py", line 1097, in next
[DEBUG 2018-04-25 11:18:47 main]     if len(self.__data) or self._refresh():
[DEBUG 2018-04-25 11:18:47 main]   File "/usr/lib64/python2.7/site-packages/pymongo/cursor.py", line 1039, in _refresh
[DEBUG 2018-04-25 11:18:47 main]     self.__max_await_time_ms))
[DEBUG 2018-04-25 11:18:47 main]   File "/usr/lib64/python2.7/site-packages/pymongo/cursor.py", line 903, in __send_message
[DEBUG 2018-04-25 11:18:47 main]     codec_options=self.__codec_options)
[DEBUG 2018-04-25 11:18:47 main]   File "/usr/lib64/python2.7/site-packages/pymongo/helpers.py", line 114, in _unpack_response
[DEBUG 2018-04-25 11:18:47 main]     raise CursorNotFound(msg, 43, errobj)
[DEBUG 2018-04-25 11:18:47 main] CursorNotFound: Cursor not found, cursor id: 164658109027
[ERROR 2018-04-25 11:18:48 main] su - apache -s /bin/bash -c pulp-manage-db failed! Check the output for error!
[ERROR 2018-04-25 11:18:48 main] Upgrade step migrate_pulp failed. Check logs for more information.
[DEBUG 2018-04-25 11:18:48 main] Exit with status code: 1 (signal was 1)
[ERROR 2018-04-25 11:18:48 main] Errors encountered during run:
[ERROR 2018-04-25 11:18:48 main] su - apache -s /bin/bash -c pulp-manage-db failed! Check the output for error!
---

Components:
satellite-capsule-6.3.1-3.el7sat.noarch
mongodb-2.6.11-2.el7sat.x86_64
mongodb-server-2.6.11-2.el7sat.x86_64
python-mongoengine-0.10.5-2.el7sat.noarch
python-pymongo-3.2-1.el7sat.x86_64
pulp-server-2.13.4.9-1.el7sat.noarch